As more U.S. states legalize marijuana, special interest groups that have a financial stake in the fight have been pushing back under the guise of fighting drug abuse.

Last week, The Nation published an interesting look at who’s driving the fight against the legalization of marijuana.

Pharmaceutical companies that make billions off painkillers and police unions are two big heavy hitters in the fight against marijuana legalization. They throw their monetary support behind groups that fight legislation that would legalize pot — even medical marijuana — and lobby Congress.